A team of special operatives, sent back in time from the future, are tasked with preventing the collapse of society. These operatives, known as travelers, enter the body of a 21st century individual moments before the individual’s “recorded time of death”. This process is referred to as a “transfer of consciousness” and cannot be used to transmit someone farther back than the 21st century. The recorded time of death is accurate to the second because of smart phones, computers, GPS, cameras, social media, and other digital pillars of the 21st century. These devices also provide knowledge of the individual who will be dying, which helps the traveler prepare for the life they will inhabit.

Without proper computing power and the back channels of the internet, the travelers would not have an accurate time of death to successfully occupy bodies moments before death. For example, the travelers cannot stop World War II, because the technology of the 1940s did not provide sufficient data to determine the exact time of recorded death, thus preventing the possession of hosts by a traveler.

The travelers must maintain their hosts’ pre-existing lives to avoid attracting attention while performing missions aimed at saving the world from a series of catastrophic events. As the series progresses, changes in the present make significantly unanticipated changes in the future.